With the scale-up of Internet, network services arise one after another, and advanced multimedia systems emerge in endlessly. Thus, the Internet needs to transfer multimedia services, such as services complying with File Transfer Protocol (FTP) which are of high burstiness, or services complying with Hypertext Transfer Protocol (HTTP) which contain image files. As to real time services in the network, which are relatively sensitive to network characteristics such as latency and jitter, transmission of FTP and HTTP services may have a great influence on them. Moreover, those multimedia services may occupy a great deal of bandwidth, which makes it difficult in the conventional network to reliably transfer some key services in need of guaranteed bandwidth.
In view of the above, diversified QoS techniques are proposed, e.g., many service models and mechanisms have been set up by IETF. Among these QoS techniques, the most approbatory one by those skilled in the art is a scheme put forward by IETF, where an Int-Serv model is applied during the access to and/or at the edge of the network, and a Diff-Serv model is applied in the core area of the network. However, the Diff-Serv model of the scheme provides priority levels to guarantee QoS, so it is difficult to guarantee transmission reliability and effect of the whole network, although the scheme is of high channel availability in the network.
In the process of allocating paths for user service streams, signal exchange of IP QoS is needed between a service control layer and a Call Manager (CM), as well as among CMs, so as to satisfy the conversation resource demand in each management domain, as well as determine the resource reservation mode according to requirements of operators. It can be seen that an IP QoS signaling process is important for guaranteeing QoS of the bearer network. However, there isn't any uniform IP QoS signalling process at present.